I don't know the answer to your question, but I do have a few comments:
1. Bravo, that took some serious balls (or you're really desperate to recover data from the drive)!
2. I hope you did that in a Class 100 (or better) clean room, or the drive probably isn't going to work for very long (assuming it works at all).
3. I'm not sure how the track-following servos on modern drives work, but I'm pretty sure that in the past replacing the head stack like that simply wouldn't work, because of slight differences in alignment between the heads in the stack (all of the heads were positioned based on the servo data from one of the heads). I *think* on a modern drive each recording surface has its own servo data (which would render this issue moot), but I am not certain of this.
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